2 *------------------------------------------------------------------
3 * af_packet.c - linux kernel packet interface
5 * Copyright (c) 2016 Cisco and/or its affiliates.
6 * Licensed under the Apache License, Version 2.0 (the "License");
7 * you may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at:
10 * http://www.apache.org/licenses/LICENSE-2.0
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 *------------------------------------------------------------------
20 #include <linux/if_packet.h>
22 #include <vlib/vlib.h>
23 #include <vlib/unix/unix.h>
24 #include <vnet/ip/ip.h>
25 #include <vnet/ethernet/ethernet.h>
27 #include <vnet/devices/af_packet/af_packet.h>
29 #define foreach_af_packet_input_error
32 #define _(f,s) AF_PACKET_INPUT_ERROR_##f,
33 foreach_af_packet_input_error
35 AF_PACKET_INPUT_N_ERROR,
36 } af_packet_input_error_t;
38 static char * af_packet_input_error_strings[] = {
40 foreach_af_packet_input_error
45 AF_PACKET_INPUT_NEXT_DROP,
46 AF_PACKET_INPUT_NEXT_ETHERNET_INPUT,
47 AF_PACKET_INPUT_N_NEXT,
54 struct tpacket2_hdr tph;
55 } af_packet_input_trace_t;
57 static u8 * format_af_packet_input_trace (u8 * s, va_list * args)
59 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
60 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
61 af_packet_input_trace_t * t = va_arg (*args, af_packet_input_trace_t *);
62 uword indent = format_get_indent (s);
64 s = format (s, "af_packet: hw_if_index %d next-index %d",
65 t->hw_if_index, t->next_index);
67 s = format (s, "\n%Utpacket2_hdr:\n%Ustatus 0x%x len %u snaplen %u mac %u net %u"
68 "\n%Usec 0x%x nsec 0x%x vlan_tci %u"
69 #ifdef TP_STATUS_VLAN_TPID_VALID
73 format_white_space, indent + 2,
74 format_white_space, indent + 4,
80 format_white_space, indent + 4,
84 #ifdef TP_STATUS_VLAN_TPID_VALID
92 buffer_add_to_chain(vlib_main_t *vm, u32 bi, u32 first_bi, u32 prev_bi)
94 vlib_buffer_t * b = vlib_get_buffer (vm, bi);
95 vlib_buffer_t * first_b = vlib_get_buffer (vm, first_bi);
96 vlib_buffer_t * prev_b = vlib_get_buffer (vm, prev_bi);
98 struct rte_mbuf * mbuf = ((struct rte_mbuf *) b) - 1;
99 struct rte_mbuf * first_mbuf = ((struct rte_mbuf *) first_b) - 1;
100 struct rte_mbuf * prev_mbuf = ((struct rte_mbuf *) prev_b) - 1;
103 /* update first buffer */
104 first_b->total_length_not_including_first_buffer += b->current_length;
106 /* update previous buffer */
107 prev_b->next_buffer = bi;
108 prev_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
110 /* update current buffer */
114 first_mbuf->nb_segs++;
115 prev_mbuf->next = mbuf;
116 mbuf->data_len = b->current_length;
117 mbuf->data_off = RTE_PKTMBUF_HEADROOM + b->current_data;
123 af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
124 vlib_frame_t * frame, u32 device_idx)
126 af_packet_main_t * apm = &af_packet_main;
127 af_packet_if_t * apif = vec_elt_at_index(apm->interfaces, device_idx);
128 struct tpacket2_hdr *tph;
129 u32 next_index = AF_PACKET_INPUT_NEXT_ETHERNET_INPUT;
133 u32 n_rx_packets = 0;
136 u32 block_size = apif->rx_req->tp_block_size;
137 u32 frame_size = apif->rx_req->tp_frame_size;
138 u32 frame_num = apif->rx_req->tp_frame_nr;
139 u8 * block_start = apif->rx_ring + block * block_size;
140 uword n_trace = vlib_get_trace_count (vm, node);
141 u32 n_buffer_bytes = vlib_buffer_free_list_buffer_size (vm,
142 VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
143 u32 min_bufs = apif->rx_req->tp_frame_size / n_buffer_bytes;
145 n_free_bufs = vec_len (apm->rx_buffers);
146 if (PREDICT_FALSE(n_free_bufs < VLIB_FRAME_SIZE))
148 vec_validate(apm->rx_buffers, VLIB_FRAME_SIZE + n_free_bufs - 1);
149 n_free_bufs += vlib_buffer_alloc(vm, &apm->rx_buffers[n_free_bufs], VLIB_FRAME_SIZE);
150 _vec_len (apm->rx_buffers) = n_free_bufs;
153 rx_frame = apif->next_rx_frame;
154 tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
155 while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs))
157 vlib_buffer_t * b0, * first_b0 = 0;
158 u32 next0 = AF_PACKET_INPUT_NEXT_ETHERNET_INPUT;
161 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
162 while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs) &&
165 u32 data_len = tph->tp_snaplen;
167 u32 bi0, first_bi0 = 0, prev_bi0;
171 /* grab free buffer */
172 u32 last_empty_buffer = vec_len (apm->rx_buffers) - 1;
174 bi0 = apm->rx_buffers[last_empty_buffer];
175 b0 = vlib_get_buffer (vm, bi0);
176 _vec_len (apm->rx_buffers) = last_empty_buffer;
180 u32 bytes_to_copy = data_len > n_buffer_bytes ? n_buffer_bytes : data_len;
181 b0->current_data = 0;
182 memcpy (vlib_buffer_get_current (b0), (u8 *) tph + tph->tp_mac + offset, bytes_to_copy);
184 /* fill buffer header */
186 b0->current_length = bytes_to_copy;
190 b0->total_length_not_including_first_buffer = 0;
191 b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
192 vnet_buffer(b0)->sw_if_index[VLIB_RX] = apif->sw_if_index;
193 vnet_buffer(b0)->sw_if_index[VLIB_TX] = (u32)~0;
195 first_b0 = vlib_get_buffer(vm, first_bi0);
198 buffer_add_to_chain(vm, bi0, first_bi0, prev_bi0);
200 offset += bytes_to_copy;
201 data_len -= bytes_to_copy;
204 n_rx_bytes += tph->tp_snaplen;
205 to_next[0] = first_bi0;
210 VLIB_BUFFER_TRACE_TRAJECTORY_INIT(first_b0);
211 if (PREDICT_FALSE(n_trace > 0))
213 af_packet_input_trace_t *tr;
214 vlib_trace_buffer (vm, node, next0, first_b0, /* follow_chain */ 0);
215 vlib_set_trace_count (vm, node, --n_trace);
216 tr = vlib_add_trace (vm, node, first_b0, sizeof (*tr));
217 tr->next_index = next0;
218 tr->hw_if_index = apif->hw_if_index;
219 memcpy(&tr->tph, tph, sizeof(struct tpacket2_hdr));
221 /* enque and take next packet */
222 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
223 n_left_to_next, first_bi0, next0);
226 tph->tp_status = TP_STATUS_KERNEL;
227 rx_frame = (rx_frame + 1) % frame_num;
228 tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
231 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
234 apif->next_rx_frame = rx_frame;
236 vlib_increment_combined_counter
237 (vnet_get_main()->interface_main.combined_sw_if_counters
238 + VNET_INTERFACE_COUNTER_RX,
241 n_rx_packets, n_rx_bytes);
247 af_packet_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
248 vlib_frame_t * frame)
251 u32 n_rx_packets = 0;
253 af_packet_main_t * apm = &af_packet_main;
255 clib_bitmap_foreach (i, apm->pending_input_bitmap,
257 clib_bitmap_set (apm->pending_input_bitmap, i, 1);
258 n_rx_packets += af_packet_device_input_fn(vm, node, frame, i);
265 VLIB_REGISTER_NODE (af_packet_input_node) = {
266 .function = af_packet_input_fn,
267 .name = "af-packet-input",
268 .format_trace = format_af_packet_input_trace,
269 .type = VLIB_NODE_TYPE_INPUT,
270 .state = VLIB_NODE_STATE_INTERRUPT,
271 .n_errors = AF_PACKET_INPUT_N_ERROR,
272 .error_strings = af_packet_input_error_strings,
274 .n_next_nodes = AF_PACKET_INPUT_N_NEXT,
276 [AF_PACKET_INPUT_NEXT_DROP] = "error-drop",
277 [AF_PACKET_INPUT_NEXT_ETHERNET_INPUT] = "ethernet-input",